LOWLAND GAME - GAPEWORM IN PHEASANTS | 700 600 500 400 300 200 100 0 0 2 4 6 8 10 Distance from feeder (metre)
frequently, compared with site 2 where hoppers were left in place for ease of access. These results highlight the importance of hygiene around communal areas and demonstrate how simple management techniques such as avoiding faecal/grain contamination, may help reduce disease risk to released birds. Though we now have a greater understanding of the epidemiology of gapeworm,
very little research has determined what effect gapeworm is having on pheasants. Detailed post-mortem examination of 180 released adult pheasants was conducted to answer this question. Birds were weighed and their tarsus length measured to obtain a body condition score by dividing body mass by tarsal length which controlled for body size, and the number of gapeworms per bird were counted. Pheasants infected with Syngamus trachea were in poorer condition than uninfected birds. Birds lost, on average 26%, (range 10-40%) of their condition (see Figure 3), losing more as the number of gapeworms per bird increased. These results suggest that gapeworm is capable of reducing pheasant body condition, which may have implications for survival and repro- ductive success of pheasants following release.
22 20 18 16 14 12 10 8 0
www.gwct.org.uk 5 10 15 20 Number of gapeworms per bird GAME & WILDLIFE REVIEW 2016 | 19 25 30 35 40 12 14 16 BACKGROUND
The gapeworm Syngamus trachea is a highly pathogenic parasite of many bird species, and is arguably the most economically important parasite of released pheasants. Infection with S. trachea can occur either directly by the ingestion of worm eggs or infective larvae, or indirectly by the ingestion of an infected invertebrate host, most commonly an earthworm. This presents a number of challenges to gamekeepers because infectious eggs and larvae can build up over time in the environment making it a difficult disease to get under control. An understanding of how this parasite is distributed spatially on estates might enable gamekeepers to mitigate disease risk with alterna- tive management techniques, poten- tially moving away from the use of anthelmintics (worming drugs). Parasites in the rearing system can reduce pheasant growth rates and condition, and though gamekeepers are aware of the losses associated with heavy gapeworm infections, very little is known about the effect of different levels of infection by this parasite on pheasants.
Figure 3
The effect of gapeworm on pheasant body condition score
Figure 2
The number of s. trachea eggs per gram of soil at site 2
Pheasant body condition
Log mean number of s. trachea eggs per gram of soil
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
